Lily Rose Beatrice Allen was born in Hammersmith, London, England. She is the daughter of actor and musician Keith Allen and film producer Alison Owen. In 1988, at the age of three, Allen appeared on The Comic Strip Presents... episode "The Yob," which her father had co-written.
In her teenage years, her musical tastes evolved from glam rock to alternative. When Allen was 11, former University of Victoria music student Rachel Santesso overheard Allen singing Wonderwall by Oasis in the school's playground; impressed, Santesso, who would later become an award-winning soprano and composer, called Allen into her office the next day and started giving her lunchtime singing lessons. At that point Allen said she knew that music was something she needed to do either as a lifelong vocation or to get it out of her system.
Allen played piano to grade 5 standard and achieved Grade 8 in singing. She also played violin, guitar and trumpet as well as being a member of a chamber choir.
Allen made an appearance as a lady-in-waiting in the 1998 film Elizabeth, which was co-produced by her mother. Allen abandoned school at age fifteen to focus on her musical performing skills and song writing, not wanting to "spend a third of her life preparing to work for the next third of her life, to set herself up with a pension for the next third of her life."
Through her father's connections, Lily signed to London Records a part of the Warner Music in 2002, but the label lost interest and she left without releasing any records.
She created several demo songs, and in late 2005, created a profile on MySpace, where she posted some of her recordings. In March 2006, OMM included an article about Allen's success through MySpace. She received her first major mainstream coverage, appearing in the magazine's cover story two months later.
After tens of thousands of MySpace views, Lily signed with Regal Recordings. In 2006, she began to work on completing what would be her first studio album. Her first mainstream single "Smile" reached the top position on the UK Singles Chart in July 2006.
Her debut record, Alright, Still, sold over 2.6 million copies and brought Allen a nomination at the Grammy Awards, BRIT Awards and MTV Video Music Awards. She then began hosting her own talk-show, Lily Allen and Friends, on BBC Three.
Her second major album release, It's Not Me, It's You, saw a genre shift for her, having more of an electropop feel, rather than the ska and reggae influences of the first one. The album debuted at #1 on the UK Albums Chart and the Australian ARIA Charts. The album spawned the hit singles "The Fear" and "Fuck You," popular mostly in Europe. It's Not Me, It's You has been praised for trying to define the times. Allen said that she does not write songs with a big picture in mind.
Allen was included on the NME Cool List for 2006. She was voted the third coolest person of the year in New Musical Express. She ranked "Number One Reason to Love '07" and "Hottest Woman of Pop/R&B." in Blender magazine. Allen was also rated number 10 on BBC Three's list of Most Annoying People of 2006. Allen was voted fourth coolest celebrity in a poll taken of 20,000 teenagers by the social networking website Bebo that was released in December 2008.
In 2009 Allen was the subject of cover stories for both Spin Magazine and Q Magazine. MTV said in February 2009 "She seems less like the model of a 21st century pop star and more like the kind of girlfriend you'd have when you're 22 – the awesome kind you'd go backpacking around Europe with, wear a sarong with. She is perfectly imperfect..."
Allen was on Esquire Magazine's list of 60 "Brilliant Brits 2009." In September of that year, Allen announced that she is considering a career in acting and that she will not renew her record contract. In a blog, her last before taking it down, Allen wrote that she has "no plans" to make another record. "The days of me making money from recording music have been and gone as far as I'm concerned." Allen's spokesperson said "She is not quitting pop music. She is not thinking about her next album right now because she is still in the middle of promoting her current record."
During autumn 2010, Allen opened a fashion rental shop "Lucy in Disguise" with her sister Sarah. In February 2010 Allen responded to a question about how her 2010 Brit Award for "British Female Solo Artist" would affect her hiatus: "This hasn't changed my plans to quit. It's actually been really good as something to work towards for the last six months, knowing I'd be doing this. It is the perfect way to say goodbye. I have so much I want to do now with my shop and record label."
In May she stated that following her remaining shows she still plans on taking a break saying "I'm ready to just take a break from it," "I'm still writing... I'm not writing for myself.."
In August a pregnant Allen banned photographers and began her hiatus following a performance at the Big Chill Festival in Herefordshire, England.
In January 2011 Allen's representatives confirmed she is launching her own record label In the Name Of. The first act signed to the label which is financially backed by Sony Music is New York noise pop act Cults.